Macrocylces, and particularly macrocyclic polyethers, are known compounds and have been referred to in the literature as "crown" compounds in reference to the crownlike appearance of the polyalkoxy cyclic chain in the molecular structural model. Such compounds are disclosed in U.S. Pat. Nos. 3,562,295, 3,686,225, and 3,687,978.
These prior art "crown" compounds are characterized as composed of alkyleneoxy chains, particularly ethyleneoxy chains, or ethyleneoxy chains upon which is fused a phenylene or cyclohexylene radical in one or more positions, examples being 2,3,11,12-dibenzo-1,4,7,10,13,16-hexoxacyclooctadeca-2,11-diene and 2,5,8,15,18,21-hexoxatricyclo-[20.4.0.sup.9.14 ] hexacosane disclosed in the U.S. Pat. No. 3,687,978. These prior compounds are known to form complexeswith a wide variety of ionic metal compounds, and they have been suggested as useful agents in carrying normally insoluble reaget substances into solution in nonhydroxylic media.
Such crown compounds have been described extensively in the literature, for example:
J. Am. Spc. 89 2495-6
J.Am. Chem. Soc. 89 7017-36
J. Am. Chem. Soc. 92 386-91
J. Am. Chem. Soc. 92 391-94
J. Org. Chem. 36 254-57
Angew. Chem. Int. Ed. 11 16-25
Fed. Proc. 27 1305-08
Endeavor 30 142-6
J.Am. Chem. soc. 92 4321-30
J. Am. Chem. Soc. 93 2231-35
J. Am. Chem. Soc. 93 2235-43
In the article, Angew. Chem. Int. Ed. 11 16-25, there is disclosed a system of nomenclature whereby such crown compounds can be referred to with greater simplicity of language than is required by the formal systems of nomenclature for organic compounds.
Although the compounds of this invention contain ethyleneoxy units, they do not possess the necessary overall structural features of "crowns". Crown compounds possess high symmetry elements, and none of their atoms are rigidly held far from the best plane of the oxygen atoms. The macrocycles described here are all asymmetric, and contain rigid planes of atoms held perpendicular to the best plane of the macrocycle, and which extend above and below that plane. Crown compounds contain patterns of ##STR1## units, and in some cases ##STR2## units. The macrocycles described here contain at least one ##STR3## each pair of carbon atoms being incorporated in a different aromtic ring. In these formulas T stands for 0. although some of the macrocycles described here possess some of the properties of crown compounds, many of the properties of the presently described macrocycles are unique, and are not shared by crown compounds.
Prior macrocycles noted above also include those which contain sulfur in the cycle in place of oxygen, and a number have been described in J. Org. Chem. 36 254-57 wherein sulfur atoms replace one to four oxygen atoms in crown-5, crown-6, and crown-7 compounds.
In the prior compounds, macrocycles containing up to 4 fused rings have been described, each ring being either a benzene or a cyclohexyl ring.
In the latter patent specifically referred to above, such macrocycles containing additional nuclear substituents on the aromatic rings are described.
The prior macrocycles are all characterized by high molecular symmetry, and have an ability to complex other substances such as metal cations, depending upon the size of the hole of the crown and the diameter of the cation. All rings fused to the crowns are situated on the periphery of the macrocycle by involvements of 1,2-linkages, or at most, 1,3-linkages. Such fused rings involve a pair of vicinal carbon atoms including broadly such rings as phenylene, naphthylene, phenylanthrylene, anthrylene, cyclohexylene, and the like.
The prior art compounds, particularly those involving peripherally fused rings, are prepared by utilizing a vicinal dihydric phenol such as catechol which is caused to react with a dihalide containing ether oxygen atoms. By selecting the appropriate dihalide and adjusting reaction conditions, the macrocycles can be formed relatively simply. More complex crowns can be formed using the vicinal dihydric phenol in which on hydroxyl group has been blocked to achieve partial reaction with the dihalide, followed by unblocking and further reaction with dihalide.